The issue is, if not wrapped correctly, you can end up with teflon threads in the fuel system which can get clogged in the injectors affecting their performance.
Once I learned that, I've never used teflon tape again on any fuel fittings. And remarkably, I've never had a fuel leak since.
This the classic case of 'Less Is More'.
It is very important that after reassembling fuel lines, with the engine off, run the fuel pump to check for leaks. If there is a leak, snug the connection more and recheck.